Method, system, and non-transitory computer-readable medium for flattening three-dimensional shoe upper template

Abstract

A method for flattening a three-dimensional shoe upper template is provided. The method includes providing a three-dimensional last model, obtaining a three-dimensional grid model, obtaining a three-dimensional thickened grid model, obtaining a two-dimensional initial-value grid model, and obtaining a two-dimensional grid model with the smallest energy value. A system and a non-transitory computer-readable medium for performing the method are also provided. The method makes it possible to precisely flatten a three-dimensional last model with a non-developable surface and thereby convert the three-dimensional last model into a two-dimensional grid model.

What is claimed is: 
     
       1. A method for flattening a three-dimensional shoe upper template, comprising the steps of:
 providing a three-dimensional last model, wherein the three-dimensional last model comprises a three-dimensional borderline, and the three-dimensional borderline comprises a three-dimensional inner feather line and a three-dimensional outer feather line; 
 performing a topological operation on the three-dimensional last model by a processing unit to obtain a three-dimensional grid model corresponding to the three-dimensional last model, wherein the three-dimensional grid model comprises a plurality of three-dimensional border grids and a plurality of three-dimensional inner grids, and each said three-dimensional border grid has a portion located on the three-dimensional borderline; 
 performing a thickening operation on the three-dimensional grid model by the processing unit to obtain a three-dimensional thickened grid model; 
 performing a dimensionality reduction operation on the three-dimensional thickened grid model by the processing unit to obtain a two-dimensional initial-value grid model; and 
 obtaining a two-dimensional grid model with a smallest energy value by the steps of:
 performing an iterative operation for finding a least-squares solution on the two-dimensional initial-value grid model by the processing unit to obtain a two-dimensional corrected grid model from each execution of the iterative operation, wherein each said two-dimensional corrected grid model comprises a plurality of two-dimensional corrected border grids corresponding to the three-dimensional border grids and a plurality of two-dimensional corrected inner grids corresponding to the three-dimensional inner grids, the two-dimensional corrected border grids of each said two-dimensional corrected grid model jointly define a two-dimensional corrected borderline, each said two-dimensional corrected borderline comprises a two-dimensional corrected inner feather line and a two-dimensional corrected outer feather line, and there is a length difference between each said two-dimensional corrected inner feather line and the three-dimensional inner feather line or between each said two-dimensional corrected outer feather line and the three-dimensional outer feather line; 
 performing an energy operation on each said two-dimensional corrected grid model by the processing unit to calculate a sum of energy of the two-dimensional corrected border grids of each said two-dimensional corrected grid model; and 
 obtaining a two-dimensional grid model with a said length difference from a plurality of said two-dimensional corrected grid models produced by the iterative operation falling within a predetermined range and with said two-dimensional corrected border grids having the smallest said sum of energy. 
 
 
     
     
       2. The method for flattening a three-dimensional shoe upper template as claimed in  claim 1 , wherein the thickening operation comprises: selecting a normal vector of each said three-dimensional border grid; and adding a predetermined thickness according to the selected normal vectors to form the three-dimensional thickened grid model. 
     
     
       3. The method for flattening a three-dimensional shoe upper template as claimed in  claim 2 , wherein the predetermined thickness is 0-1 mm. 
     
     
       4. The method for flattening a three-dimensional shoe upper template as claimed in  claim 1 , wherein the sum of energy corresponding to a said execution of the iterative operation is determined to be the smallest if a log 10  of an absolute value of a difference between the sum of energy corresponding to the execution of the iterative operation and the sum of energy corresponding to a previous said execution of the iterative operation is less than −1. 
     
     
       5. The method for flattening a three-dimensional shoe upper template as claimed in  claim 1 , wherein the predetermined range for said length differences is 0-10 mm. 
     
     
       6. The method for flattening a three-dimensional shoe upper template as claimed in  claim 1 , wherein the iterative operation is executed 1-50 times. 
     
     
       7. A system for flattening a three-dimensional shoe upper template, comprising:
 a memory for storing at least one computer program including a plurality of instructions; 
 a processing unit for executing the instructions:
 provide a three-dimensional last model, wherein the three-dimensional last model comprises a three-dimensional borderline, and the three-dimensional borderline comprises a three-dimensional inner feather line and a three-dimensional outer feather line; 
 perform a topological operation on the three-dimensional last model to obtain a three-dimensional grid model corresponding to the three-dimensional last model, wherein the three-dimensional grid model comprises a plurality of three-dimensional border grids and a plurality of three-dimensional inner grids, and each said three-dimensional border grid has a portion located on the three-dimensional borderline; 
 perform a thickening operation on the three-dimensional grid model to obtain a three-dimensional thickened grid model; 
 perform a dimensionality reduction operation on the three-dimensional thickened grid model to obtain a two-dimensional initial-value grid model; and 
 obtain a two-dimensional grid model with a smallest energy value by:
 performing an iterative operation for finding a least-squares solution on the two-dimensional initial-value grid model to obtain a two-dimensional corrected grid model from each execution of the iterative operation, wherein each said two-dimensional corrected grid model comprises a plurality of two-dimensional corrected border grids corresponding to the three-dimensional border grids and a plurality of two-dimensional corrected inner grids corresponding to the three-dimensional inner grids, the two-dimensional corrected border grids of each said two-dimensional corrected grid model jointly define a two-dimensional corrected borderline, each said two-dimensional corrected borderline comprises a two-dimensional corrected inner feather line and a two-dimensional corrected outer feather line, and there is a length difference between each said two-dimensional corrected inner feather line and the three-dimensional inner feather line or between each said two-dimensional corrected outer feather line and the three-dimensional outer feather line; 
 performing an energy operation on each said two-dimensional corrected grid model to calculate a sum of energy of the two-dimensional corrected border grids of each said two-dimensional corrected grid model; and 
 obtaining a two-dimensional grid model with a said length difference from a plurality of said two-dimensional corrected grid models produced by the iterative operation falling within a predetermined range and with said two-dimensional corrected border grids having the smallest said sum of energy; and 
 
 
 a user interface generated by the processing unit. 
 
     
     
       8. The system for flattening a three-dimensional shoe upper template as claimed in  claim 7 , wherein the thickening operation comprises: selecting a normal vector of each said three-dimensional border grid; and adding a predetermined thickness according to the selected normal vectors to form the three-dimensional thickened grid model. 
     
     
       9. The system for flattening a three-dimensional shoe upper template as claimed in  claim 8 , wherein the predetermined thickness is 0-1 mm. 
     
     
       10. The system for flattening a three-dimensional shoe upper template as claimed in  claim 7 , wherein the sum of energy corresponding to a said execution of the iterative operation is determined to be the smallest if a log 10  of an absolute value of a difference between the sum of energy corresponding to the execution of the iterative operation and the sum of energy corresponding to a previous said execution of the iterative operation is less than −1. 
     
     
       11. The system for flattening a three-dimensional shoe upper template as claimed in  claim 7 , wherein the predetermined range for said length differences is 0-10 mm. 
     
     
       12. The system for flattening a three-dimensional shoe upper template as claimed in  claim 7 , wherein the iterative operation is executed 1-50 times. 
     
     
       13. A non-transitory computer-readable recording medium for storing at least one computer program including a plurality of instructions to be executed by a processing unit, wherein the instructions, when executed by the processing unit, cause the processing unit to:
 provide a three-dimensional last model, wherein the three-dimensional last model comprises a three-dimensional borderline, and the three-dimensional borderline comprises a three-dimensional inner feather line and a three-dimensional outer feather line; 
 perform a topological operation on the three-dimensional last model to obtain a three-dimensional grid model corresponding to the three-dimensional last model, wherein the three-dimensional grid model comprises a plurality of three-dimensional border grids and a plurality of three-dimensional inner grids, and each said three-dimensional border grid has a portion located on the three-dimensional borderline; 
 perform a thickening operation on the three-dimensional grid model to obtain a three-dimensional thickened grid model; 
 perform a dimensionality reduction operation on the three-dimensional thickened grid model to obtain a two-dimensional initial-value grid model; and 
 obtain a two-dimensional grid model with a smallest energy value by:
 performing an iterative operation for finding a least-squares solution on the two-dimensional initial-value grid model to obtain a two-dimensional corrected grid model from each execution of the iterative operation, wherein each said two-dimensional corrected grid model comprises a plurality of two-dimensional corrected border grids corresponding to the three-dimensional border grids and a plurality of two-dimensional corrected inner grids corresponding to the three-dimensional inner grids, the two-dimensional corrected border grids of each said two-dimensional corrected grid model jointly define a two-dimensional corrected borderline, each said two-dimensional corrected borderline comprises a two-dimensional corrected inner feather line and a two-dimensional corrected outer feather line, and there is a length difference between each said two-dimensional corrected inner feather line and the three-dimensional inner feather line or between each said two-dimensional corrected outer feather line and the three-dimensional outer feather line; 
 performing an energy operation on each said two-dimensional corrected grid model to calculate a sum of energy of the two-dimensional corrected border grids of each said two-dimensional corrected grid model; and 
 obtaining, from a plurality of said two-dimensional corrected grid models produced by the iterative operation, a two-dimensional grid model with a said length difference falling within a predetermined range and with said two-dimensional corrected border grids having the smallest said sum of energy. 
 
 
     
     
       14. The non-transitory computer-readable medium as claimed in  claim 13 , wherein the thickening operation comprises: selecting a normal vector of each said three-dimensional border grid; and adding a predetermined thickness according to the selected normal vectors to form the three-dimensional thickened grid model. 
     
     
       15. The non-transitory computer-readable medium as claimed in  claim 14 , wherein the predetermined thickness is 0-1 mm. 
     
     
       16. The non-transitory computer-readable medium as claimed in  claim 13 , wherein the sum of energy corresponding to a said execution of the iterative operation is determined to be the smallest if a log 10  of an absolute value of a difference between the sum of energy corresponding to the execution of the iterative operation and the sum of energy corresponding to a previous said execution of the iterative operation is less than −1. 
     
     
       17. The non-transitory-computer-readable medium as claimed in  claim 13 , wherein the predetermined range for said length differences is 0-10 mm. 
     
     
       18. The non-transitory-computer-readable medium as claimed in  claim 13 , wherein the iterative operation is executed 1-50 times.